Coexistence of the α and δ phases in an as-cast uranium-rich U–Zr alloy

Uranium–zirconium alloys are being investigated for use in ultrahigh burn-up, metallic inert matrix nuclear fuels. Characterization of these alloys in the transmission electron microscope with spatial resolutions that are inaccessible by other techniques shows that the orthorhombic α and hexagonal, intermetallic δ phases coexist in an as-cast uranium-rich U-10 wt.% Zr alloy. Analyses reveal the chemistries of and crystallographic relationship between the two phases.